Turning Alaskan Birch Sap into Syrup, Part 2

(This is Part 2, focusing on cooking the sap down to syrup.  To read about collecting the sap, please enjoy the prior article).

In our neck of the woods, the sap started running on April 2, 2016, more than 2 weeks earlier than in recent years and 6 weeks earlier than a particularly late spring several years ago.  Whenever Nature decides, we have to be ready.

Assembling the evaporator

Fortunately, we had strung the collection lines among two dozen trees in February and early March.  After that, Bryan started to assemble the "woodstove" he bought from Leader Evaporator (in Vermont), which consisted of a sheet metal exterior, about 600 pounds of heat resistant bricks (some of which he had to cut to fit), and a short, metal chimney.

Unfortunately, the masonry cannot be cemented together until the temperature rises above the mid-40s, which did not occur regularly until late March, and once that occurred, it started to rain!  Every day for a week!  So that set us back a bit.

The evaporator was finally finished and the first test fire ignited on April 1.
The very next day, we discerned drops of sap flowing down the plastic lines to the collection tank next to the wood  stove. Phew!  Perfect timing.

Collecting Birch Sap for Syrup, Part 1

In 2013, I wrote a blog article about collecting birch sap in the spring to make beer.  Since that topic has continued to attract hundreds of readers, particularly this time of year, I thought an update might be in order, especially now that we have “amped up” collection to hundreds of gallons and now enjoy the delicious syrup, too.

Whereas collecting a few gallons of sap from a few trees is very cheap and easy to do, and nutritionally/flavorfully worthwhile for residents of a boreal forest, collecting enough and cooking it down to syrup is a huge endeavor, perhaps better suited to a business or affinity group. Below is our experience over several years.

The previous collection method

In  2013, we picked four trees close together, tapped them, and let the sap drip into a vinegar bottle we bungee corded beneath each tap and thus collected an initial 2.5 gallons. Because we were so pleased with the flavor, nutritional value, and versatility of the sap, the next two years, we “uppped” our take to 15 gallons, collected by a length of food grade tubing connecting each tap to a five gallon bucket at the foot of each tree.  We collected our target amount in only 3 or 4 days. Easy in, easy out.

Five gallons were immediately deployed as the liquid (replacing water) in a batch of home brewed spring beer.  (Bryan reports that he could not discern a difference in flavor or texture from the 2013 batch of 1/2 water and 1/2 sap, but he enjoys the contrast to his chimay recipe made with 100% water.)  It  has an initial taste of wood and banana.  The banana flavor recedes, but a pleasingly light woodiness and sweetness remain.